94 



POLAR PROBLEMS 



per cent. As will be explained further, the fast-ice has its greatest 

 width along the Siberian coast and especially opposite the mouth 

 of the Yana River, where it extends outward 270 miles from shore. ^ 



What Each Class Consists of 



Fast-ice is horizontally immobile young ice attached to the shore. 

 It develops in width outward from the shore from the beginning of the 

 formation of new ice until the end of November or the beginning of 



Fig. 4— The Arctic Pack at the nortli pole on May 12, 1926. Oblique view from the Norge. CPhoto- 

 graph from Lincoln Ellsworth.) 



December and constantly increases in thickness until May. Conse- 

 quently it consists of new ice, with parts of pack ice (former fast-ice) 

 embedded in it that remained in the coastal waters until the time of 

 the formation of new ice and have been caught by the new ice at the 

 moment of its formation. 



Pack ice in the broad meaning of the term denotes any sea ice 

 "which has drifted from its original position" (Priestley).^ In the 

 Arctic Sea it represents the movable sea ice consisting partly of rem- 

 nants of broken fast-ice and partly of newly formed ice among these 

 floating remnants. In summer, when fast-ice does not yet exist as 

 an immovable part of the ice cover of the Arctic Sea, all movable, 

 floating ice between the coast and the Arctic Pack is pack ice. In 



^ The only islands within the bounds of the Arctic Pack are the isolated, outpost islands Ben- 

 nett, Jeannette, Henrietta, and Zhokhov. In the pack-ice belt lie the northernmost islands of Spits- 

 bergen and Franz Josef Land, Lonely Island, Northern Land, Little Taimyr Island (Tsesarevich 

 Alexei Island), Wrangel Island, and the northwestern edge of the American Arctic Archipelago. With- 

 in the fast-ice belt lie the offshore islands of the Kara and Siberian Seas (including in the latter the 

 New Siberian Islands) and the islands along the northern coast of Alaska. 



3 Work by Wright and Priestley cited in the bibliography at the end of this article, especially 

 Chapters 9, 10, and 11 by Priestley. 



